Fabric shredding apparatus



Oct. 29, 1963 R. c. ATKINSON FABRIC SHREDDING APPARATUS Filed June 8, 1961 4 Sheets-Sheet l F G. l INVENTOIZ P/CHADD C. ATKINSON ZU VMVM Oct. 29, 1963 R. c. ATKINSON 3,108,330

FABRIC SHREDDING APPARATUS Filed June 8, 1961 4 Sheets-Sheet 2 FEGZ /N VE' N 7' 0E RICHARD C. A TKINSON Oct. 29, 1963 R. c. ATKINSON 3,108,330

FABRIC SHREDDING APPARATUS Filed June 8, 1961 4 Sheets-Sheet 3 FIG. 3

/N VE N TOD RICHAQD C A TK/NS 0N A TTOQNE YS.

4 Sheets-Sheet 4 Filed June 8, 1961 VOE INVEN TOP RICHARD C. A771 INSON A TTOENEYS.

United States Patent 3,103,330 FABRHI SHREDEHNG APPARATUS Richard C. Atkinson, Lynwood, Calif., assignor, by mesne assignments, to (Irornpton 3: Knowles (Iorporation, Worcester, Mass, a corporation of Massachusetts Fried Eune 8, wet, Ser. No. 115,784} 3 (Claims. (til. 19-33) This invention relates to apparatus for shredding fabrics, coarse fibrous materials, and the like, to produce commercially usable fibers. It relates more particularly to an apparatus of this type having improved mechanism for feeding the material to be shredded to the usual shredding cylinder. 7

The material to be shredded by such apparatus may be of various kinds, such as woven, non-woven or knitted fabrics, or fibrous material such as jute butts, bagasse and other fibrous materials which must be processed through a shredding operation to make them commercially usable as fibers. For convenience and without limitation, all such materials are referred to herein as fabrics. The fibers from which the fabric is made may be wool, cotton, jute, linen, sisal, etc., or synthetic fibers.

The stock from the shredding apparatus is usually processed through subsequent garnetting or carding steps so as to produce yarn or various types of batting. The degree of shredding accomplished in the initial operation substantially affects the cost of maintaining the cards and garnets and also affects the quality of the finished material. It is important that the material be shredded with a minimum of fiber breakage and that the quantity of unshredded stock be held to a minimum.

A conventional fabric shredding apparatus comprises a feed roll which is provided on its periphery with a series of projecting pins or teeth. Below the feed roll is an anvil rigidly secured to the frame on which the feed roll is rotatably mounted. This anvil extends partly around the feed roll periphery and forms with the feed roll a passage through which the fabric is delivered, by the teeth of the rotating roll, over a breaker bar secured to the anvil. The breaker bar extends lengthwise of the feed roll and is located between the latter and a shredding cylinder having peripheral shredding teeth. The shredding cylinder is driven about an axis parallel to the rotation axis of the feed roll and in such a direction that the shredding teeth strike the fabric while the latter is restrained by the teeth of the feed roll and engaged by the breaker bar, thereby shredding the fabric continuously as it is fed over the breaker bar by the feed roll. "0 accommodate irregularities in the thickness of the fabric, the feed roll is mounted for vertical movements in the frame and is spring loaded against upward movement away from the anvil, whereby the feed roll will be displaced upwardly against the springs as the result of a relatively thick piece of fabric being fed through the arcuate passage between the feed roll and the anvil.

The conventional apparatus described above has several disadvantages. Due to the spring loading of the feed roll and the fact that it will be raised to accommodate any thick piece of fabric stock, any thinner pieces of stock simultaneously fed to the shredding cylinder will not be restrained by the teeth or pins of the feed roll and therefore will be snatched by the shredder teeth without being shredded. Also, due to the heavy weight of the shredding cylinder and the high speed at which it is driven, the shredding teeth must be specially processed to resist the impact which occurs when the teeth strike a heavy scam in the fabric, and breakage of some of the shredding teeth often results even with such special processing of the teeth. In addition, the quality of the shredded stock from the conventoinal apparatus is not entirely satisfactory for all purposes in that the fibers tend to be unduly reduced in length through breakage of the fibers on the rigid breaker bar under the action of the shredding teeth.

The principal object of the present invention is to provide a fabric shredding apparatus which overcomes the above-noted disadvantages of such apparatus as made heretofore.

In an apparatus made according to the invention, the feed roll and the shredding cylinder may be of conventional form. However, in place of the usual anvil or breaker bar holder, 1 provide a series of segments pivotally mounted on a shaft extending generallypar-allel to the axes of the feed roll and shredding cylinder. These segments are disposed in substantially end-to-end relation on the shaft to define with the feed roll the fabric feeding passage extending partly around the roll periphery, and the segments have portions disposed between the shredding cylinder and feed roll to form a segmented breaker bar to which the feed passage leads. Each segment is pivotable in one direction about the common shaft to enlarge the part Of the fabric feeding passage defined by this segment; and biasing means are operativeiy connected to the segments for urging them in the opposite direction about the shaft and against stop means, the latter serving to hold the segments so that their breaker bar portions are normally in alignment with each other along the space between the feed roll and shredding cylinder.

With the new construction, it is unnecessary to spring load the feed roll to accommodate different thicknesses of the stock being fed, because each segment can yield by pivoting against its biasing means so as to enlarge the corresponding part of the feed passage through which a relatively thick piece of fabric happens to be fed. Thus, a particular segment can yield to accommodate a rela tively great thickness of fabric passing over that segment, without affecting the other segments over which fabric of normal thickness is passing, whereby the latter segments continue to maintain the corresponding parts of the feed passage at their normal size so that the fabric is adequately gripped or restrained by the teeth of the feed roll. Moreover, the segmented breaker bar of the new construction is adapted to yield locally under abnormal impact of the shredding teeth on a seamed or other more resistant part of the fabric.

These and other features of the invention will be better understood by reference to the accompanying drawings, in which:

FIG. 1 is a vertical cross-sectional view of a preferred form of the new fabric shredding apparatus, with parts broken away;

FIG. 2 is an elevational view of the apparatus shown in FIG. 1, as seen from the right in FIG. 1 and with parts broken away; and

FIGS. 3 and 4 are perspective views of one of the pivoted segments shown in FIGS. 1 and 2.

The apparatus as illustrated comprises a frame having two opposed end sections, one of which is shown at 10 in FIGS. 1 and 2. A conventional feed roll 11 is rotatably mounted on the frame between the end sections, the feed roll being provided with the usual series of teeth 12 closely spaced around the roll periphery. The feed roll 11 as shown is hollow and has a stub shaft 13 secured in each end of the roll, each stub shaft being rotatably mounted in suitable bearings in an upper part .14 of the adjacent frame section 10 (FIG. 1). Opposite the feed roll ill is a shredding cylinder 15 rotatably mounted on the frame and adapted to be driven at high speed about an axis parallel to the rotation axis of the feed roll. The shredding cylinder 15 is shown as being of the conventional type having on its periphery a series of shredding teeth 16.

A shaft 18 is mounted on the frame and extends between the end sections to which the opposite ends of the shaft are secured. The shaft 18 is parallel to the rotation axes of the feed roll 11 and shredding cylinder 15 and carries a plurality of segments of which two are shown at 19 and 1%. These segments are adapted to pivot or swing on the shaft and are disposed in closely adjacent end-to-end relation. The segments 19 and 19a have portions 21 and Zita, respectively, disposed between the shredding cylinder 15 and the feed roll 11 to form a segmented breaker bar. It will be understood that while -I have shown only two segments 19'19o on the shaft 18, the latter is provided with any desired number of these segments in abutting relation along substantially the entire distance from the frame end section 10 to the opposing end section (not shown) of the frame. ius, the pivoted segments on the shaft 18 extend along substantially the entire length of the feed roll 11 directly below the feed roll, and the portions 20, 20a, etc., of these segments form a segmented cutting edge or breaker bar extending along the space between the shredding cylinder 15 and feed roll H, from one end to the other of this space. As shown in FIG. 2, the segment 19 at one end of shaft 18 abuts a part 10a of the frame end section 11 it being understood that the segment at the opposite end of shaft 18 similarly abuts a corresponding part of the opposing frame end section, so that the pivotally mounted segments are held in substantially end-to-end relation.

A bracket 21 is bolted to the frame end section '10 and is provided with a pair of spaced ribs or guides 22. One end of a cross member 23 is disposed between the guides 22 and is seated on the end of a screw 21a threaded through the bottom of bracket 21. The other end of cross member 23 is guided and supported in a similar bracket (not shown) bolted to the opposing frame end member (not shown). Accordingly, by adjustment of the supporting screw 21a at each end of the member 23, the latter may be moved toward or away from the overlying segments 19, 19a, etc., while maintaining this cross member substantially parallel to the shaft 18.

A series of screws 24- are threaded in the cross member 23 and are spaced along the latter so that there are two screws '24 below each segment 19, 19a, etc. Each screw 24 extends into the lower end of a coiled compression spring 25 and carries a nut 26 on which the lower end of the spring is seated. At its upper end, each spring 25 bears against the lower surface of the overlying segment, where it is held in position by a stud 27 secured in a hole in the corresponding segment and having an enlarged head projecting into the upper end of the coiled spring. As shown in FIG. 1, the springs 25 act to urge the corresponding segments clockwise aibout the shaft 18, thereby urging the segmented cutting edge or breaker bar 21), 20a, etc., upwardly into the space between shredding cylinder 15 and feed roll 11.

The segments 12-41% are provided with arms 29 and 29a, respectively, which are rigidly secured to the segments below shaft 118 and project generally horizontally away from the shaft and the shredding cylinder 15. These arms extend over a second cross member 31 rigidly secured to the frame end members and extending parallel to the adjustable cross member 23. A series of screws 30 are threaded through cross member 31 and are spaced along this member so that each arm 22, 29a, etc., overlies the head of a corresponding screw so, against which the arm is urged by the two springs 25 of the corresponding pivoted segment. Each screw 30, therefore, forms an adjustable stop for limiting upward movement of the corresponding breaker bar segment 20 or 20a, etc., under the action of the corresponding springs 25.

The details of the pivoted segments 1%, 19a, etc., which are identical to each other, are shown more clearly in FIGS. 3 and 4 illustrating the segment 19. As there shown, the segment is somewhat elongated horizontally and is provided at one end portion with a transverse bore 33 for receiving the shaft 18. On its bottom surface at this same end portion, the segment has a pair of integral cars 34 depending from the segment and spaced from each other to receive between them one end of the corresponding arm 29. The arm 2? is rigidly secured to the segment by rivets or bolts extending through holes 34a in the ears and through the arm. At its opposite end portion, the segment 19 is provided with a transverse slot 35 extending downwardly from the upper surface of the segment and adapted to receive the segment 21) forming the breaking or cutting edge. The segment 20 is releasably secured in any desired manner in the slot 35 so as to enable replacement of this segment. Between the end portions of the segment 19, its upper surface 36 is concave so that it corresponds approximately to the peripheral curvature of the overlying cylindrical feed roll 11. Thus, as shown in FIG. 1, the concave upper surfaces of the segments form with the feed roll a fabric feeding passage 3'7 extending partly around the feed roll to the segmented cutting edge 20, 20a, etc.

In the operation of the apparatus as illustrated, the shredding cylinder 15 is driven clockwise (FIG. 1) at high speed, and the feed roll 11 is driven clockwise at a lower speed to retard the feeding of the fabric and thereby prevent the fabric from being snatched by the shredding teeth 16 without being shredded. The fabric is fed into passage 37 at the right-hand side of this passage as seen in FIG. 1 and is picked up by the teeth 12 of the overlying feed roll. The fabric is thus fed through the passage 37 and over the segmented cutting edge 20, 20a, etc., whereby the fabric is shredded by the action of the teeth 16 on the shredding cylinder.

The material to be shredded is normally heavily compressed and is fed to the shredding cylinder 15 in irregularly sized pieces of irregular thickness. When a relatively thick piece of material is fed through passage 37, the segment 19 or 19a, etc., which happens to underlie this thick piece is displaced downwardly by pivoting on shaft 13 against the action of the corresponding springs 25, thereby accommodating this relatively thick piece of fabric without affecting the other segments. Consequently, these other segments continue to hold the overlying fabric in position to be restrained by the teeth 12 of the feed roll, so that the teeth 16 of the shredding cylinder 15 cannot snatch the fabric from the feed passage 37 without effecting the desired shredding action. It will be apparent that the amount of downward displace ment of a segment under the action of a relatively thick piece of material will depend upon the thickness of this piece, and such downward displacement does not appreciably affect the shredding action on the relatively thick piece, since the corresponding cutting edge or segment 20, 20a, etc., is simply lowered somewhat relative to the other segments and continues to perform its breaking or cutting function in cooperation with the shredding teeth 16. As soon as the relatively thick piece of material has passed through the feed passage 37 and is replaced by thinner material, the springs 25 return the corresponding segment to its normal position against the corresponding stop 30.

As shown in FIGS. 1 and 2, it is assumed that a relatively thick piece of material is passing through the feed passage 37 directly above the segment 19a, so that the latter is displaced downwardly against its springs 25 relative to the adjacent segment 19 which is not influenced by the relatively thick piece of material. This downward displacement of the segment 1%, by pivoting on the shaft 18, results in its arm 29a being raised somewhat from the stop 313a (FIG. 2), while the arm 29 of the unaffected segment 19 continues to be held against its stop 31 by the corresponding springs 25.

The new apparatus thus provides a substantially uniform pressure of the feed roll 11 across the entire width of the stock being shredded and eliminates any snatching of unshredded stock by the teeth of the shredding cylinder.

ioreover, the springs or biasing means 25 aiford a desirable cushioning action which prevents excessive impacts during the shredding operation. That is, if a heavy seam in the material is fed over one of the breaking or cutting segments 20, 20a, for example, the corresponding springs 25 permit this segment to yield under the action of the shredding teeth striking the heavy seam, thereby cushioning the impact and preventing or reducing breakage of the shredding teeth. The cushioning action of the biasing means 25 also results in improvement in the quality of the shredded stock by preventing excessive reduction in the fiber length. Additionally, since the segmented breaker bars 20, 2011, etc., are substantially shorter than the conventional breaker bar for an apparatus of the same capacity, a broken or worn breaker bar segment can be replaced more cheaply.

It will be observed that the biasing force of the springs 25 on each segment 19, 1911, etc., may be adjusted independently of the other segments by simply adjusting the corresponding nuts 26 on their respective bolts 24, these nuts forming individual adjusting means for the respective springs. Thus, by such adjustment in conjunction with adjustment of the corresponding stop 30, unequal Wear of the cutting edges 20, 20a, etc., can be compensated while maintaining substantially uniform biasing forces on the respective segments. Moreover, the screw 21a supporting each end of the spring-supporting cross member 23 forms a means for adjusting the latter member bodily to vary the biasing force exerted by all the springs, thereby permitting adjustment of the shredding action.

I claim:

1. Apparatus for shredding fabrics and the like, which comprises a shredding cylinder rotatable about the cylinder axis and having peripheral shredding teeth, a feed roll mounted for rotation about an axis substantially parallel to the cylinder axis and having peripheral teeth for feeding the fabric to the shredding teeth, the cylinder and roll being spaced from each other to form an intervening elongated space toward which fabric from the feed roll is directed by the shredding teeth incident to rotation of the cylinder, a shaft extending generally parallel to said axes, a plurality of breaker bar segments pivotally mounted on the shaft and extending in substantially endto-end relation along said space in position to engage the fabric fed by said roll and acted upon by the shredding teeth, each segment being pivotable in one direction about the shaft under impact of the shredding teeth on fabric engaged by said segment, a plurality of biasing springs for the respective segments and each of which is operable to bias the corresponding segment in the opposite direction about the shaft independently of the other segments, adjustable stops for limiting movements of the respective segments in said opposite direction by the respective springs, a common supporting member for the springs, first adjusting means for adjusting each spring relative to the supporting member independently of the other springs, to permit individual adjustment of the biasing force exerted by each spring on the corresponding segment, and second adjusting means for adjusting the supporting member bodily to vary said biasing force exerted by all the springs.

2. Apparatus according to claim 1, in which said first adjusting means include a threaded element supporting each spring on said supporting member.

3. Apparatus according to claim 1, comprising also a stationary frame movably mounting said supporting member, said second adjusting means including a threaded element on the frame operable to move the supporting member relative to the frame.

References Cited in the file of this patent UNITED STATES PATENTS 365,784 Bourne July 5, 1887 587,085 Atherton July 27, 1897 1,672,704 Allen et al June 5, 1928 1,740,644 Brooks Dec. 24, 1929 2,912,720 Vandergriff et al Nov. 17, 1959 FOREIGN PATENTS 770,463 Great Britain Mar. 20, 1957 

1. APPARATUS FOR SHREDDING FABRICS AND THE LIKE, WHICH COMPRISES A SHREDDING CYLINDER ROTATABLE ABOUT THE CYLINDER AXIS AND HAVING PERIPHERAL SHREDDING TEETH, A FEED, ROLL MOUNTED FOR ROTATION ABOUT AN AXIS SUBSTANTIALLY PARALLEL TO THE CYLINDER AXIS AND HAVING PERIPHERAL TEETH FOR FEEDING THE FABRIC TO THE SHREDDING TEETH, THE CYLINDER AND ROLL BEING SPACED FROM EACH OTHER TO FORM AN INTERVENING ELONGATED SPACE TOWARD WHICH FABRIC FROM THE FEED ROLL IS DIRECTED BY THE SHREDDING TEETH INCIDENT TO ROTATION OF THE CYLINDER, A SHAFT EXTENDING GENERALLY PARALLEL TO SAID AXES, A PLURALITY OF BREAKER BAR SEGMENTS PIVOTALLY MOUNTED ON THE SHAFT AND EXTENDING IN SUBSTANTIALLY ENDTO-END RELATION ALONG SAID SPACE IN POSTION TO ENGAGE THE FABRIC FED BY SAID ROLL AND ACTED UPON BY THE SHREDDING TEETH, EACH SEGMENT BEING PIVOTABLE IN ONE DIRECTION ABOUT THE SHAFT UNDER IMPACT OF THE SHREDDING TEETH ON FABRIC ENGAGED BY SAID SEGMENT, A PLURALITY OF BIASING SPRINGS FOR THE RESPECTIVE SEGMENTS AND EACH OF WHICH IS OPERABLE TO BIAS THE CORRESPONDING SEGMENT IN THE OPPOSITE DIRECTION ABOUT THE SHAFT INDEPENDENTLY OF THE OTHER SEGMENTS, ADJUSTABLE STOPS FOR LIMITING MOVEMENTS OF THE RESPECTIVE SEGMENTS IN SAID OPPOSITE DIRECTION BY THE RESPECTIVE SPRINGS, A COMMON SUPPORTING MEMBER FOR THE SPRINGS, FIRST ADJUSTING MEANS FOR ADJUSTING EACH SPRING RELATIVE TO THE SUPPORTING MEMBER INDEPENDENTLY OF THE OTHER SPRINGS, TO PERMIT INDIVIDUAL ADJUSTMENT OF THE BIASING FORCE EXERTED BY EACH SPRING ON THE CORRESPONDING SEGMENT, AND SECOND ADJUSTING MEANS FOR ADJUSTING THE SUPPORTING MEMBER BODILY TO VARY SAID BIASING FORCE EXERTED BY ALL THE SPRINGS. 